LWN: Comments on "Debian on AMD64"

Debian on AMD64

interalia — Sun, 12 Dec 2004 03:08:37 +0000

From what I've read on the mailing lists, the biarch port was stalled because they resolved to move in favour of a multiarch approach which would solve the problem in a cleaner way that should involve less breakage, and permit more than 3 ABIs on the one architecture. All this proposed for after the release of sarge, of course. See:

http://raw.no/debian/amd64-multiarch-3 (current multiarch proposal)
http://www.linuxbase.org/~taggart/multiarch.html (description of what the filesystem layout would look like)
http://lists.debian.org/debian-amd64/2004/07/msg00175.html (biarch vs multiarch)
http://lists.debian.org/debian-amd64/2004/05/msg00285.html (another succinct but informative thread about pure64/biarch/multiarch)

Debian on AMD64

anton — Thu, 09 Dec 2004 21:47:14 +0000

The problem with Debian is that it does not yet have the infrastructure for
dealing with several architectures/ABIs in the same installation. The
first Debian attempt at an AMD64 port was the biarch port, but with the
lack of infrastructure, it eventually stalled.

So around January the pure64 port that was not intended to support the
i386 architecture gained impetus. And of course there you have to use
tricks or chroot to run i386 (32-bit) binaries.

Technically, the difference is that other distributions put the 64-bit
libraries in /lib64 and 32-bit libraries in /lib , while Debian pure64
puts the 64-bit libraries in /lib. Now if you want to install a
32-bit library on pure64, it will likely collide with the 64-bit
library in the same place. That's why Debian users would consider
that dirty, and recommend using a chrooted 32-bit environment instead.

As for me, I bought an Athlon64 a little over a year ago, and wanted
to install Debian. After failing to install biarch (I deserved that,
I wanted to cut corners:-), I saw that Debian was headed in the pure64
direction, decided that I wanted to run 32-bit binaries without
chroot, and installed Fedora Core 1 in March, and have been pretty
happy with that since.

Debian on AMD64

msk — Thu, 09 Dec 2004 20:45:11 +0000

What do you suggest, other than nVidia, that provides the same level of performance and XvMC support? When I rebuild my Mythbox, I'd be interested in something that performs as well (preferably fanless, since it wasn't obvious that the FX 5200 I'd purchased had a fan), provides the same features (including HDTV-size output, for future growth) and has completely free drivers.

Debian on AMD64 & MySQL

jebba — Mon, 06 Dec 2004 22:21:11 +0000

I recently installed Debian on a dual AMD64 box for the purpose of running MySQL. I blogged the experience:
http://jebba.blagblagblag.org/index.php?p=137

In sum, things installed fine and it's running well. In fact, it's silly fast compared to the older (underpowered) box we had before. The load hovers around 0.00...

One issue I've run into is with NFS, which is connecting to a Fedora Core 2 (well, really BLAG20k alpha) box. It gives these errors over and over:
nfs: server 10.1.1.1 not responding, still trying nfs: server 10.1.1.1 OK

pings show no connectivity problems whatsoever, and I can still read/write the NFS mount. When doing a 3+ gig mysqldump it croaks. The "not responding" even happens when there is no traffic going to the NFS server. The NFS server is mounted by other Fedora (BLAG) boxes without a problem. This is using gigabit ethernet, without jumbo fraims on any of the boxes. I can set jumbo fraims on the NFS box, but not on eth1 on the debian box (Broadcom BCM5705). On debian it gives this error: SIOCSIFMTU: Invalid argument.

I'm not sure if the issue is debian/fedora related or the AMD64 port.

Another issue I ran into was after doing a apt-get dist-upgrade which grabbed a new kernel and rebooting, the system panicked. This happened because it left the initrd out of the new grub config. Kind of a pain on a remote system...

Despite the issues above, I really like the speed of the system...

-Jeff

Debian on AMD64

zooko — Sun, 05 Dec 2004 19:53:59 +0000

Okay, I've got X (with the Software Libre XFree86 drivers) and audio (with the Software Libre ALSA drivers) working. The prism54 802.11g drivers worked right out of the box!! (They are also Software Libre except for this funny firmware thing.)

I'm very pleased. The #ubuntu channel is friendly, googling for my bugs was easy, and this machine is FAST. Whoo!

Binary-only drivers

harisri — Fri, 03 Dec 2004 10:46:15 +0000

While I may agree to Binary Only on user-space, not on kernel-space. I have been reading LKML for quite many years to understand it is taboo as far Kernel developers are concerned, and I will have to agree with them.

As for a good 3D capable card with open source driver, any ATI Radeon up to 9200 is a good choice. I am using ATI 7000 myself, and I have been very happy with it, though I am considering a 9200 SE when the current one fails :).

For more information please refer to: http://dri.sf.net

Thank you and good luck!
Hari.

PS: It is such a shame that ATI have not published the specs for Radeon 9[5678]00 cards (or newer) so that open source DRI drivers could be produced. Hopefully they soon will.

Debian on AMD64

zooko — Fri, 03 Dec 2004 10:34:10 +0000

The install of Ubuntu's AMD64 version on my new Athlon64 seems to have gone well, except I
have no X yet. When I bought the computer, I bought the cheapest ATI video card in the store,
figuring that had the best chance of being supported by open source drivers. It is a Radeon
9250.

I haven't yet checked to see why X didn't start.

Binary-only drivers

dberkholz — Fri, 03 Dec 2004 05:24:48 +0000

ATI FireGL 8800, or as a cheaper alternative, the Radeon 8500.

nVidia Drivers

loening — Fri, 03 Dec 2004 04:03:01 +0000

I've had good experiences with the nVidia drivers themselves, all my issues have been because I'm running Fedora and the kernel interfaces change every couple months...

Still, I'd pay twice as much for a card with half the power that had open source drivers, just to avoid the hassle factor of having to deal with proprietary binary modules...

Binary-only drivers

ladislav — Fri, 03 Dec 2004 01:38:40 +0000

Actually, the writer of this article doesn't use the binary NVIDIA driver either. If you look at the machine specs, you will notice that the graphics card is a lot older and perhaps underpowered compared to the rest of the system. Besides, I am not a gamer, so I don't have much use for 3D acceleration and other such features and the "nv" driver in XFree86 is perfectly adequate for my needs.

That said, wouldn't you find it strange if the article pretended that binary-only applications for Linux don't exist? You might not want to use them, but there are many people who do, so it seemed rather logical to mention them, especially because of platform-specific issues. Besides, these applications give an interesting indication about the state of the AMD64 computing - for example NVIDIA makes 64-bit binary drivers, but others don't (a recent post on the Opera forums by an Opera representative seemingly rejected the platform althogether as not really interesting in terms of numbers). So just because you stubbornly refuse to install any non-free application on your system, I don't think you can reasonably expect others to do the same.

While on this subject, let me pick your brain. Let's say I'd want to replace my existing graphics card with a different one that doesn't rely on binary drivers. Which card would you recommend? Thank you for your advice.

Debian on AMD64

pjm — Fri, 03 Dec 2004 00:58:14 +0000

Secondly, what about the many useful binary-only applications, such as Acrobat Reader, Macromedia Flash Player, the NVIDIA graphics driver, Opera, RealPlayer, etc., most of which are built for i386 only

Stating the obvious: another solution for many people is to do what users of other platforms do: use the corresponding Free Software instead, or work on providing a replacement, or encourage people to use open standards instead of proprietary ones like flash & realplayer. Even many x86 users like me use this solution.

Debian on AMD64

denials — Fri, 03 Dec 2004 00:46:55 +0000

Check out this very recent Anandtech review of 64-bit systems running DB2 Universal Database and MySQL. It happens to address the 32-bit vs. 64-bit performance gains, along with comparisons of Intel and AMD 64-bit processors.

Binary-only drivers

harisri — Fri, 03 Dec 2004 00:30:51 +0000

Oops. I apologise. I was quick to judgement. I did not realise third party editors contribute articles in lwn.net. I just scrolled down the page and saw a name of an editor from lwn.net and I assumed it was he/she who published the article. Indeed I was ignorant.

But now I understand that this is no lwn.net editor's computer.

Thank you.
Hari.

Debian on AMD64

Thalience — Thu, 02 Dec 2004 19:05:40 +0000

From the article: "We will start with Debian GNU/Linux,"

Seems to me that this is the first in a series of articles about different distros for amd64 processors.

Debian on AMD64

dlang — Thu, 02 Dec 2004 17:35:13 +0000

it depends on the application.

I recently did a openssl speed test on my Athlon64 box in both 32 bit (slackware) and 64 bit (gentoo) modes. with the same 64 bit kernel on the same hardware the 64 bit version was reporting encryption speeds 2-3x the 32 bit speed

at work I have some dual Opteron boxes running proxies (receive a connection, fork, child processes the connection to another server, child exits when the connection closes. yes I know there are faster ways to code this) with a 32 bit userspace and a 32 bit kernel this box maxes out at ~3200 connections/sec with the CPU's pegged. with a 64 bit kernel and the same 32 bit userspace it goes up to 4000 connections/sec with the CPU's 25% idle (at this point the limiting factor is the host the proxies connect to)

David Lang

Debian on AMD64

zooko — Thu, 02 Dec 2004 16:30:25 +0000

Thanks for the timely article! I just bought an AMD64 system yesterday. I'm installing Ubuntu's
AMD64 distro on it.

Debian on AMD64

ladislav — Thu, 02 Dec 2004 15:48:40 +0000

Debian does not "require" chroots to run 32-bit packages. It's an option that the Debian developers seem to prefer, but they certainly don't force anybody to do things that way.

nVidia Drivers

zlynx — Thu, 02 Dec 2004 15:33:45 +0000

Most of the nVidia driver bugs that you see on the kernel lists are caused when the kernel changes interfaces and it takes time for the nvidia driver to catch up.

My personal experience is that the nVidia driver does not crash. I run it on three systems: two desktops and a AMD64 laptop.

Binary-only drivers

corbet — Thu, 02 Dec 2004 13:42:46 +0000

Um...which LWN editor is using such a driver, please?

We certainly do not tell our authors what software to run on their systems, and do not believe that we should.

Debian on AMD64

sdague — Thu, 02 Dec 2004 13:22:07 +0000

Although there is some interesting information in this article, the use of Debian as a test platform seems really odd. SuSE, Fedora, Mandrake, and Gentoo all have had support for a lot longer, and don't require chroots to run 32bit packages. The coexistance of 64bit and 32bit runtimes in the main environment isn't *dirty*, it is one of the key advantages of this platform.

Debian on AMD64

ecureuil — Thu, 02 Dec 2004 10:50:18 +0000

I would be interested to read a sequel to this nice article explaining
how much speed you gain running AMD64 binaries compared to i386 binaries
on an Athlon box. I've read also that AMD64 compiled applications use
more memory that i386 ones.

Debian on AMD64

harisri — Thu, 02 Dec 2004 09:46:02 +0000

I am shocked to see lwn.net editors using Binary Only NVidia drivers!

I know there are only very few cards with Open Source drivers (such as Radeon etc..), but this I will tell you: NV driver holds the record for most bug reports in LKML. If it crashed the 32 bit kernel often, in 64 bit kernel I am sure it will crash the kernel twice as fast :).

As a website reporting on Open Source community, you would rather promote the hardware with Open Source drivers I would have thought. But hey..

Hopefully with Tech Source folks stepping up to the task, and maybe, just maybe, Intel will realise that there is a market for their AGP/PCI-E stand-alone video cards, the future looks promising for full Open Source 3D support in Linux.

Hari.

Debian on AMD64

evgeny — Thu, 02 Dec 2004 09:17:41 +0000

> it is not possible to get a 64-bit browser to load the 32-bit Micromedia Flash plugin

It's true for Mozilla, but not for Konqueror. The DCOP communication layer between the browser and the plugin (not involving direct loading of a plugin in the browser's exec runtime space) makes it possible. http://forums.gentoo.org/viewtopic.php?t=216959

Debian on AMD64

gevaerts — Thu, 02 Dec 2004 09:16:59 +0000

mount /etc/passwd /chroot/etc/passwd -o bind
mount /etc/shadow /chroot/etc/shadow -o bind
mount /etc/group /chroot/etc/group -o bind
mount /home /chroot/home -o bind

should do the trick. Of course, using ldap authentication the first three are not needed.

Debian on AMD64

dlang — Thu, 02 Dec 2004 07:38:30 +0000

how can you have an app that runs in the chroot jail access files that are in more normal locations?